Hitherto, an identification label comprising a metal face plate having stamped thereon patterns, or a heat-resistant plastic sheet or a metal plate having thereon patterns formed with a curable ink is known. However, when a production system is changed to a system of producing many kinds of products with a small amount each, it is difficult to provide each identification label according to circumstances and there is a problem that the production of identification labels cannot deal with the production system of the many kinds of products with small amount each.
On the other hand, labels are known, each prepared by forming heat transferred patterns comprising a wax-based ink on a label sheet having an ink-receiving layer comprising a mixture of a styrene-polyolefin copolymer and a thermoplastic resin having a melting point of at least 200.degree. C. as described in JP-A-62-299391 (the term "JP-A" as used herein means an "unexamined published Japanese patent application") or a label sheet having an ink-receiving layer comprising a mixture of an epoxy resin or the like, hydrophobic silica, and a low density polyethylene wax as described in JP-A-63-176183.
However, the labels each having the ink-receiving layer described above have the problem that they are poor in a solvent resistance, whereby the patterns are vanished by a washing step with a solvent or a wiping step thereof to lose the function as the labels.